background: cytokines and specially interferon-gamma (ifn-g) are largely responsible for the regulation of the protective im­mune response against mycobacterial infections. several studies have clarified the importance of common variants of ifn- g gene regarding the susceptibility to tuberculosis. bacille calmette-guérin (bcg) vaccine that is used to prevent se­vere forms of tuberculosis could ...

background programmed cell death (apoptosis) is a physiological process needed to remove unwanted or damaged cells. it has been hypothesized that any failure of programmed cell death leads to the development of neoplasm. identifying new agents which induce apoptosis in tumor cells is of great significance in treatment of neo­plasms. numerous studies suggest that exposure of tumor cells to stati...

background: considering the role of t cells in the pathogenesis of periodontitis, the purpose of this study was to compare the amount of ifnγ, il4 and il17 in advanced periodontal lesions with healthy gum areas to determine each th1, th2 and th17 cells activity in comparison with each other and finally, to compare the value and the role of humoral, cell mediate and autoimmune responses.     met...

background: currently available radioprotectors are poorly tolerated in man and the general use of aminothiols is compromised by their side effects. this study was carried out to test and compare the radioprotective potential of cimetidine and famotidine against lethally gamma irradiated nmri mice. materials and methods: adult male nmri mice in groups of 10 were exposed to various doses of gamm...

Decay rates of the positronium molecule $\text{Ps}_{2}$ into two photons and an electron-positron pair are determined. Previous studies find that these very different, \[ \Gamma\left(\text{Ps}_{2}\to e^{+}e^{-}\right)/\Gamma\left(\text{Ps}_{2}\to\gamma\gamma\right)\simeq250\text{ (previous studies)}. \] This is puzzling since both processes have body final states same order in fine structure co...